Effects of sublethal exposure to metofluthrin on the fitness of Aedes aegypti in a domestic setting in Cairns, QueenslandReportar como inadecuado




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Parasites and Vectors

, 10:274

First Online: 31 May 2017Received: 19 December 2016Accepted: 25 May 2017DOI: 10.1186-s13071-017-2220-7

Cite this article as: Buhagiar, T.S., Devine, G.J. & Ritchie, S.A. Parasites Vectors 2017 10: 274. doi:10.1186-s13071-017-2220-7

Abstract

BackgroundMetofluthrin is highly effective at reducing biting activity in Aedes aegypti. Its efficacy lies in the rapid onset of confusion, knockdown, and subsequent kill of a mosquito. In the field, there are a variety of scenarios that might result in sublethal exposure to metofluthrin, including mosquitoes that are active at the margins of the chemical’s lethal range, brief exposure as mosquitoes fly in and out of treated spaces or decreasing efficacy of the emanators with time. Sublethal effects are key elements of insecticide exposure and selection.

MethodsThe metofluthrin dose for each treatment group of male and female Ae. aegypti was controlled using exposure time intervals to a 10% active ingredient AI metofluthrin emanator. Room size and distance from the emanator for all groups was maintained at 3 m. In bioassay cages, male Ae. aegypti were exposed at 0, 5, 10, 20, 30 and 40-min intervals. Females were exposed in bioassay cages at 0, 10, 20, 30, 40 and 60-min intervals. Mortality rates and fecundity were observed between the exposure time groups for both sexes.

ResultsFemale Ae. aegypti exposed for 60 min had a significantly higher mortality rate 50%, after a 24-h recovery period, than other exposure times, 10, 20, 30 and 40 min P < 0.001. An overall difference in fecundity was not observed in females between treatments. A significant effect on male mortality was only observed at 40 min exposure times, three meters from the 10% AI emanator \ \left\overset{-}{X}=98\%,\kern0.5em P<0.001 ight \. Males that survived metofluthrin exposure were as likely to produce viable eggs with an unexposed female as males that had not been exposed P > 0.05.

ConclusionRegardless of sex, if a mosquito survived exposure, it would be as biologically successful as its unexposed counterpart. Portability of the metofluthrin emanator and delayed knockdown effects create opportunities for sublethal exposure and potential pyrethroid resistance development in Ae. aegypti, and should be taken into consideration in recommendations for field application of this product, including minimum exposure periods and a prescribed number of emanators per room based on volume.

KeywordsMetofluthrin Spatial repellents Pyrethroid-resistance Aedes aegypti Dengue AbbreviationsAIActive ingredient

SEStandard error





Autor: Tamara S. Buhagiar - Gregor J. Devine - Scott A. Ritchie

Fuente: https://link.springer.com/







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